IN SUBSECTION MACROPHYLLAE- FASCICULATAE from NORTHERN SOUTH AMERICA Lankesteriana International Journal on Orchidology, Vol

Lankesteriana International Journal on Orchidology ISSN: 1409-3871 [email protected] Universidad de Costa Rica Costa Rica

Wilson, Mark; Baquero, Luis; Dupree, Katharine; Jiménez, Marco M.; LeBlanc, Cheryl M.; Merino, Gilberto; Portilla, Jose; Salas Guerrero, Marcos; Tobar Suárez, Francisco; Werner, Jon D. THREE NEW SPECIES OF PLEUROTHALLIS (ORCHIDACEAE: PLEUROTHALLIDINAE) IN SUBSECTION MACROPHYLLAE- FASCICULATAE FROM NORTHERN SOUTH AMERICA Lankesteriana International Journal on Orchidology, vol. 16, núm. 3, 2016, pp. 349-366 Universidad de Costa Rica Cartago, Costa Rica

Available in: http://www.redalyc.org/articulo.oa?id=44349421005

How to cite Complete issue Scientific Information System More information about this article Network of Scientific Journals from Latin America, the Caribbean, Spain and Portugal Journal's homepage in redalyc.org Non-profit academic project, developed under the open access initiative LANKESTERIANA 16(3): 349—366. 2016. doi: http://dx.doi.org/10.15517/lank.v16i3.27314

THREE NEW SPECIES OF PLEUROTHALLIS (ORCHIDACEAE: PLEUROTHALLIDINAE) IN SUBSECTION MACROPHYLLAE- FASCICULATAE FROM NORTHERN SOUTH AMERICA

Mark Wilson1,10, Luis Baquero2, Katharine Dupree1, Marco M. Jiménez3, Cheryl M. LeBlanc4, Gilberto Merino5, Jose Portilla6, Marcos Salas Guerrero7, Francisco Tobar Suárez8 & Jon D. Werner9 1 Department of Organismal Biology and Ecology, Colorado College, Colorado Springs, CO 80903, U.S.A. 2 Jardin Botanico de Quito, Pasaje #34, Rumipampa E6-264 y Av Shyris, Interior Parque La Carolina, Quito, Ecuador 3 Av. del Ejército y Juan Izquierdo, 190102, Zamora, Ecuador 4 Department of Biology, Ball State University, Muncie, IN 47306, U.S.A. 5 EquaflorA, Pedro Álvarez Cabral 1-69 Y Av. Don Bosco, Cuenca Ecuador 6 Ecuagenera, Km. 2 1/1 Vía a Cuenca Sector Llampasay, Gualaceo, Ecuador 7 Nature and Culture International, Chachapoyas, Peru 8 Arupos, E2 y Av. Yaloman, Quito, Ecuador 9 8117 Northway SW, Lakewood, WA 98498, U.S.A. 10 Author for correspondence: [email protected]

Abstract. The history of the taxonomy of Pleurothallis R.Br. subsection Macrophyllae-Fasciculatae and recent descriptions in that group are summarized. The phylogenetic position of the group based on preliminary molecular data and the appropriateness of the proposed genera Acronia C.Presl. and Zosterophyllanthos Szlach. & Marg. for this group are discussed. Three new species from northern South America are described: Pleurothallis rubrifolia from southeastern Ecuador and northeastern Peru; Pleurothallis nangaritzae from southeastern Ecuador; and Pleurothallis castanea. Labellar micromorphology examined by scanning electron microscopy for P. rubrifolia and P. nangaritzae is discussed in relation to taxonomy and possible pollinator interactions.

Key words: Acronia, Macrophyllae-Fasciculatae, Pleurothallidinae, Pleurothallis, SEM, Zosterophyllanthos Introduction. In his initial reorganization of the (2001) created the genus Zosterophyllanthos Szlach. genus Pleurothallis R.Br., Luer (1986) retained & Marg. for Pleurothallis subsection Macrophyllae- section Macrophyllae-Fasciculatae of subgenus Fasciculatae, based in part upon the bilobed stigma, a Pleurothallis, created by Lindley (1859). characteristic trait of this group. A total of 189 species Subsequently, Macrophyllae-Fasciculatae was were transferred to that genus (Kolanowska, Pérez- demoted to a subsection within section Pleurothallis, Escobar, Sánchez & Szlachetko 2011, Szlachetko joining subsections Acroniae, Antenniferae, & Kulak 2006 a, b, Szlachetko & Margonska Longiracemosae and Macrophyllae-Racemosae 2001, Szlachetko, Veyret, Mytnik-Ejsmont, (Luer 1988). However, a few years later Luer (2005) Sawicka, Rutkowski & Baranow 2012). Apart elevated subsections Acroniae and Macrophyllae- from Pleurothallis allenii L.O.Williams, species of Fasciculatae to generic level under the resurrected Pleurothallis subsection Acroniae were not moved name Acronia C.Presl., creating under it sections to the new genus, this being the major distinction Acronia, Amphigya and Macrophyllae-Fasciculatae. between the taxonomies of Luer (2005) and the Luer (2005) recognized 213 species in Acronia Szlachetko group (Szlachetko & Margonska 2001, section Macrophyllae-Fasciculatae at that time. Szlatcheko & Kulak 2006 a, b). In an alternate approach, Szlachetko and Margonska The molecular phylogenetic study of the

Received 31 October 2016; accepted for publication 5 December 2016. First published online: 8 December 2016. Licensed under a Creative Commons Attribution-NonCommercial-No Derivs 3.0 Costa Rica License. 350 LANKESTERIANA

Pleurothallidinae by Pridgeon, Solano & Chase 2014) and Stelis species (Ignowski 2015, Ignowski, (2001) included only three species from Pleurothallis de Brito, Bona & de Camargo Smidt 2015), labellar subsection Macrophyllae-Fasciculatae, Pleurothallis micro-morphology has not been examined to cardiantha Rchb.f., Pleurothallis cardiothallis Rchb.f. date in Pleurothallis subsection Macrophyllae- and Pleurothallis teaguei Luer. In the phylogeny based Fasciculatae. Of particular interest in the labellar on nrDNA ITS these species grouped closely with the micro-morphology of some Pleurothallidinae is type of genus Pleurothallis, Pleurothallis ruscifolia the so-called “glenion”, described by Luer (1986) R.Br. Consequently, Pleurothallis subsection as a “well-demarcated, more or less circular Macrophyllae-Fasciculatae was included in the structure, on the front surface of the lip just above circumscription of Pleurothallis (Pridgeon & Chase the base and positioned beneath the stigma”. Luer 2001, Pridgeon, Cribb, Chase & Rasmussen 2005). (1986) speculated that “in all likelihood it plays The ongoing phylogenetic studies of Pleurothallis an important role in attracting the pollinator” and by Wilson et al. (2011, 2013) and Wilson (unpubl. Duque (2008) that “perhaps the glenion facilitates data), incorporating a much more extensive sampling the entry of the visitor to this area”. While in Stelis of species from the subgenera included in this some progress has been made in the understanding circumscription, support the inclusion of subsection of the morphology and function of the glenion at the Macrophyllae-Fasciculatae within Pleurothallis. base of the hypochile (Ignowski et al. 2015), almost In other words, the available evidence does not nothing is known about the glenion of Pleurothallis support the elevation of subsection Macrophyllae- subsection Macrophyllae-Fasciculatae. Fasciculatae to the level of genus, either along with In this paper we describe three new species subsection Acroniae under genus Acronia (Luer 2005) of Pleurothallis from subsection Macrophyllae- or alone as genus Zosterophyllanthos (Kolanowska et Fasciculatae and present preliminary data on labellar al. 2011, Szlachetko & Kulak 2006 a, b, Szlachetko micro-morphology and glenion structure. & Margonska 2001, Szlachetko et al. 2012) In the decade or so since the revision of Materials and Methods Pleurothallis subsection Macrophyllae-Fasciculatae Collections of plant material —. Material collected (Luer 2005) ten new species have been described in in Ecuador (collections #2020, #2095 and #2050) this group: four under Pleurothallis (Pleurothallis were made under investigation permit #018-2016-IC- anthurioides A.Doucette; Pleurothallis adventurae FLO-FAU-DPAZCH-UPN-VS/MA granted to Karremans & Bogarín; Pleurothallis gigiportillae EcuaCorriente S.A. (ECSA). Specimens were A.Doucette & J.Portilla; and Pleurothallis oscarii moved under the transportation permit #UPN-VS- Archila & Chiron); five under Acronia (Acronia GM-025-2016 granted to and managed by Ecotono, barbosae Luer & Thoerle; Acronia miniatura Luer, Ecuador. Material from Peru was collected under a Thoerle & F.Werner; Acronia rinkei Luer; Acronia permit #N 292-2016-SERFOR/DGGSPFFS granted rhinocera Luer & Sijm; and Acronia tobarii Luer to Marcos Salas Guerrero by the Servicio Nacional & Hirtz); and one under Zosterophyllanthos Forestal y de Fauna Silvestre (SERFOR), Peru. Plants (Zosterophyllanthos dariensis Kolan. & Szlach). were also imported into the U.S.A. through purchases All these species described under Acronia and from Ecuagenera (Gualaceo, Ecuador), EquaflorA Zosterophyllanthos have subsequently been (Cuenca, Ecuador) and Mundiflora (Cuenca, Ecuador) transferred to Pleurothallis. Depending on and grown in the collections of Wilson and Werner. synonymy, there are currently between 223 and Material from these latter plants was used for the 297 species attributable to Pleurothallis subsection creation of herbarium specimens accessioned into Macrophyllae-Fasciculatae. the herbarium at Colorado College (COCO). Flowers While labellar micro-morphology has been were preserved in Kew Mix (5% formalin [37.6% examined in some Pleurothallidinae, such as in formaldehyde], 53% methanol, 5% glycerol, 37% Brazilian Octomeria species (Cardoso-Gustafson deionized water).

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Morphology and taxonomic comparisons —. Results Living material of each collected species was The labellum or “lip” of Pleurothallis rubrifolia examined by the first author in the collections of is quite unique, even when imaged with conventional Ecuagenera, EquaflorA, and Mundiflora, as well macro-photography (Figs. 3c, 4b, 5b, 6). The as in the collection of imported plants at Colorado “glenion”, a small depression in the hypochile just College. These materials were used for creation of in front of the anther, is oval in shape and is elevated the Lankester composite digital plates (LCDPs) significantly above the surrounding depression and for morphological and taxonomic comparisons. on a callus. In SEM (Fig. 7) the glenion appears Photographs were taken with a Canon EOS 40D to consist of three concentric layers of different using a Canon 100 mm f2.8 macro-lens and cell types, surrounded by a depression with cells extension tubes as required. In order to determine forming a smooth surface. The elevated areas of novelty, these species were compared to a database the lip consist of papillae which increase in packing of species descriptions, photographs and scans of density outward from the depression, creating types amassed by the first author over a 10-year another smooth surface. With conventional macro- period, as well as all pertinent literature, including photography the lip of Pleurothallis nangaritzae but not limited to: Bennet and Christenson (1993); is observed to possess a bilobed glenion, a rare Dodson (2003); Dodson and Dodson (1980, 1982, character in Pleurothallis subsection Macrophyllae- 1991); Escobar (1994, 2006); Luer (1974, 1975a, b, Fasciculatae, and a few papillae along the outer 1976, 1977, 1986, 1988, 2005, 2009, 2011); Luer edges. In SEM, it is apparent that papillae cover a and Thoerle (2013); Schweinfurth (1959, 1970); significant portion of the lip surface and surround and Zelenko and Bermudez (2009). Floras and a triangular area of smooth tissue, with the glenion other taxonomic materials from Colombia and Peru at the base (see images under the Discussion). The were included, because of the possibility that some cellular structure of the glenion itself was not visible of the species in the collections of Ecuagenera, due to a covering of dehydrated liquid, presumably EquaflorA and Mundiflora may be originally from the secretions of the glenion. The lip of derived from those two countries and do not in fact Pleurothallis castanea was not imaged. occur naturally in Ecuador. Such appears to be the case with Pleurothallis neorinkei A.Doucette (from Taxonomy Colombia) Doucette et al. (2016) and Pleurothallis Pleurothallis rubrifolia Mk.Wilson, Tobar & Salas papillingua A.Doucette and J.Portilla (from Peru) Guerr., sp. nov. (Figs. 2-8). (Wilson, unpubl. data). Species were compared in detail to those with which they may be confused, TYPE: Ecuador. Vivero ECSA, Tundayme, such as the Pleurothallis cardiostola Rchb.f. Gualaquiza, Morona Santiago, elevation, complex (Fig. 1–2), or have been confused, such as 822 m, 78º25’52.18”W 3º34’3.14”S, Sept. 2016, F. Pleurothallis canidentis Luer & R.Escobar. Tobar & M. Jiménez 2020 (holotype: QCNE!; isotype: QCA!). Scanning electron microscopy —. Fresh-harvested flowers were preserved in Kew Mix. For scanning Pleurothallis rubrifolia is superficially similar to electron microscopy (SEM) flowers were dehydrated the species of the Pleurothallis cardiostola complex, in successively higher concentrations of ethanol including the species Pleurothallis adelphe Luer & (80%, 95%, 100%, 100%) for 15 min each before Hirtz, Pleurothallis perforata Luer & Hirtz (syn. being placed in freshly-opened 100% ethanol. Acronia adelphe (Luer & Hirtz) Luer) and Pleurothallis Specimens were dehydrated in a critical point dryer lanigera Luer & Hirtz and can be distinguished by (EMS 850) prior to mounting and sputter coating. several factors. P. rubrifolia can be distinguished from Specimens were imaged using a Jeol JSM-6390LV P. perforata by the absence of a circular cavity in the scanning electron microscope with an accelerating mesochile or “disc” of the lip; the abaxial surface of voltage of 10-15 kV. the leaf reddish in P. rubrifolia vs. green in all the P.

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Figure 1. Drawings of Pleurothallis cardiostola-complex species: A. Pleurothallis cardiostola; B. Pleurothallis lanigera; C. Pleurothallis adelphe; D. Pleurothallis perforata. From Luer 2005. Courtesy of Missouri Botanic Gardens Press.

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Figure 2. Comparison of Pleurothallis castanea (A) and Pleurothallis lanigera (B). Photographs by Mark Wilson. cardiostola complex species; the mature leaf with a mm, glabrous, 7-veined; Petals yellow-brown to channel or depression towards the base in which the darker brown, moderately to heavily infused with flower rests in P. rubrifolia vs. no depression in P. maroon-burgundy along vein, oblanceolate, slightly cardiostola complex species. falcate, acute, entire along the margins, 2.0-2.3 × 6.0-6.4 mm, glabrous, 1-veined; Lip brown to intense Plant medium in size, to ca. 29 cm tall, epiphytic, burgundy-brown, triangular, obtuse, entire along caespitose; Roots fibrous; Ramicaul terete, 7.2-19.0 the margins, 3.0-4.0 × 3.5-4.5 mm, glenion oval cm long, enclosed by papyraceus basal sheath 3.0-3.8 with raised callus surrounded by a depressed area, cm long; Leaves sub-erect/ascendant, ovate, 8.3-11.5 central channel; Column burgundy-brown with pale × 3.9-5.8 cm, acute, cordate, slightly revolute along edge, stout, 1.5-2.5 × 1.5 mm, bilobed stigma, apical margins, coriaceous, adaxially mottled dark green, anther, anther cap yellow, viscidium pale yellow; abaxially red-brown, channeled about midrib in basal Capsule 4.6 cm long. half; Inflorescence one-flowered, from reclining spathaceous bract 11-13 mm long, pedicel 6-9 mm Additional material studied: Ecuador. Natural forest long; Flower 1.4-1.7 × 1.4-1.5 cm, resupinate, flower near the waste dump in the northeast of project ECSA, resting in depression formed by channel in leaf; Tundayme, Gualaquiza, Morona Santiago, elevation, Dorsal sepal yellow-brown with maroon-burgundy 1466 m, 78º25’52.18”W 3º34’3.17”S, Sept. 2016, infused along veins to darker brown with extensive F. Tobar & M. Jiménez 2095 (paratype: QCNE!; maroon-burgundy at base and along veins, ovate, paratype: QCA!). Plant flowered in cultivation at subacute, entire along the margins, 6.5-8.0 × 6.0- Ecuagenera as Pleurothallis canidentis, without 7.5 mm, glabrous, 5-veined; Synsepal yellow-brown collection data M. Wilson & J. Portilla PL0971 with maroon-burgundy infused along veins, ovate, (paratype: HA!). Plants purchased from Ecuagenera as obtuse, entire along the margins, 4.0-6.0 × 6.5-8.0 P. canidentis and flowered in cultivation at Colorado

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Figure 3. Lankester composite digital plate of Pleurothallis rubrifolia: A. Whole flower. B. Floral dissection. C. Lip and column. D. Partially dehiscent capsule. E. Whole plant illustrating red abaxial leaf surface. Prepared by Mark Wilson from the paratypes Wilson & Portilla PL0748 and Wilson & Portilla PL0971.

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Figure 4. Pleurothallis rubrifolia in situ near Tundayme, Ecuador: A. Whole plant among roots of Arecaceae. B. Flower. Photographs by Francisco Tobar.

Figure 5. Pleurothallis rubrifolia in situ in Valle de Los Chilchos, Leimebamba. Peru. A. Flower on leaf. B. Flower detail. Photographs by Marco Salas.

College M. Wilson & J. Portilla PL0177 and PL0748 Etymology: In reference to the unique red coloration (paratypes: COCO!). Peru. Albazo, Valle de Los on the abaxial leaf surface. Chilchos, Leimebamba, Cachapoyas, Salas Guerr. Distribution and habitat: Pleurothallis rubrifolia 0127 (paratype:USM!). has been recorded for Tundayme, Ecuador (Fig. 13)

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Conservation status: The type locality of Pleurothallis rubrifolia in Ecuador (Fig. 14) is within a conservation zone associated with EcuaCorriente copper-mining concession, Project Mirador, that may or may not be secure in the future. However, the abundance and breadth of distribution from southeastern Ecuador into northeastern Peru suggest that the species is not threatened in situ at this time. The species is widely distributed in collections in the U.S.A. and Europe under the name Pleurothallis canidentis, but the level of genetic diversity in these plants is probably very low, most of the plants originating from Ecuagenera, hence there is some concern regarding the ex situ conservation status of P. rubrifolia.

Pleurothallis rubrifolia is easily distinguished from Pleurothallis canidentis, with which it has been confused in the commercial trade, by the smaller plant Figure 6. Lip and column detail for Pleurothallis rubrifolia (A. glenion; B. callus). Photograph by Mark Wilson. size; slightly smaller leaf size; the lip brown-burgundy, triangular and planar in P. rubrifolia vs. red-brown and Leimebamba, Chachapoyas, Amazonas, Peru. In or orange, oblong and convex in P. canidentis; the Ecuador, the species grows in very humid premontane glenion raised, surrounded by callus in P. rubrifolia vs. and montane forests in the Cordillera del Cóndor from slightly raised with no distinct surrounding callus in P. ~800-1700 m elevation, among the roots of Arecaceae. canidentis; and petals, dorsal sepal, synsepal yellow- In Peru, it grows in very humid lower montane forest brown to darker brown, moderately to heavily infused on the eastern slope of the Andes, from 1478-2015 with maroon-burgundy along the veins in P. rubrifolia m elevation, in association with plants from family vs. dorsal sepal canary yellow, petals and synsepal red- Clusiaceae. brown in P. canidentis.

Figure 7. A–B. Scanning electron micrographs of lip and column of Pleurothallis rubrifolia. SEM images by Katy Dupree.

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Figure 8. Drawing of Pleurothallis rubrifolia: A. Whole flower. B. Column (¾ view). C. Lip (top view); D. Floral dissection. E. Whole plant. Drawing by Cheryl Marie LeBlanc, prepared from the paratype Wilson & Portilla PL0748.

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Pleurothallis castanea Mk.Wilson, G.Merino & of European and North American trees of the genus J.D.Werner, sp. nov. (Figs. 2A, 9–10) Castanea Mill.

TYPE: Ecuador. Flowered in cultivation at EquaflorA, Distribution and habitat: At this time, Pleurothallis without collection data, October 20, 2016, M. Wilson castanea is only known from live collections in & G. Merino PL0981 (holotype: HA!). Ecuador. When describing species from greenhouse collections which have no locality information Pleurothallis castanea can be distinguished from or accompanying in situ observation one must Pleurothallis cardiostola by the glabrous sepals and petals in P. castanea vs. cellular-glandular to coarsely consider the possibility of a greenhouse hybrid. We believe that the characteristics of this Pleurothallis pubescent in P. cardiostola; the longer sepals and petals in P. castanea; and the leaf ovate in P. castanea are sufficiently distinct from the other species of the Pleurothallis cardiostola complex to make the vs. ovate to lanceolate in P. cardiostola. P. castanea is possibility that this represents a hybrid between two also similar to Pleurothallis lanigera Luer & Hirtz, but species of the complex highly unlikely. Further, all differs in the sepals and petals, glabrous in P. castanea the plants observed at Ecuagenera and EquaflorA vs. markedly pubescent in P. lanigera. were very consistent in morphology, which would not Plant medium in size, to ~16-30 cm tall, caespitose; be the case were they seedlings from an unintentional Roots fibrous; Ramicaul 13-29 cm long, enclosed by or intentional greenhouse hybrid. We are convinced, papyraceus basal-sheath 4 cm long and mid-sheath 4 therefore, that P. castanea represents a novel species cm long; Leaves deflexed, spreading, cordate, apex and we will continue to seek field records to confirm long acuminate, entire along the margins, 6.9-10.0 × that this species occurs in situ and to determine a 4.3-7.0 cm, glabrous, coriaceous, the blade slightly distribution for the species. The species should not, concave; Inflorescence one-flowered from sub-erect however, be added to the flora of Ecuador at this time, spathe 1.5 cm long; Flower non-resupinate, 2.8-3.0 since it is conceivable the species was obtained from × 1.8-2.5 cm; Dorsal sepal chestnut, broadly ovate, Colombia or Peru and does not occur naturally in obtuse, slightly revolute along apical and lateral Ecuador. margins, 1.8 × 1.5 cm, glabrous, 9-veined; Synsepal Conservation status: In the absence of locality data chestnut, ovate, obtuse, shortly apiculate, slightly we cannot assess the in situ conservation status of P. revolute along the apical and lateral margins, 1.8 × castanea. The ex situ conservation status is of concern, 1.5 cm, glabrous, 7-veined; Petals chestnut, obovate- since while the species occurs in two collections in unguiculate, truncate-rounded, 12 × 5 mm, glabrous, Ecuador, it is known from only one collection in 3-veined; Lip chestnut, ovate-triangular, 1.0 × 1.0 cm, the U.S. and it is quite likely that all of these plants with a prominent broadly triangular depression, the originated from a single original plant. surface of which is verrucose, the glenion a small and bilobed cavity in front of the anther; Column cream- Pleurothallis nangaritzae M.Jiménez, Tobar & beige suffused with pink at base, stout, 8 x 8 mm, with Mk.Wilson, sp. nov. (Figs. 11–13). a bilobed stigma, anther apical, anther cap pale yellow, viscidium orange. TYPE: Ecuador: Near the Nangaritza River, Zamora- Chinchipe, Ecuador, 1500 m, October 16th, 2016, F. Additional material studied: Ecuador. Flowered in Tobar and M. Jiménez 205 (holotype: QCNE!). cultivation at Ecuagenera, without collection data, Mk.Wilson & J.Portilla PL0958 (paratype: COCO!). Pleurothallis nangaritzae is recognized by its Purchased from EquaflorA asPleurothallis cardiostola large leaf size to flower size ratio; glossy, heavily Rchb.f. and flowered in cultivation by Jon Werner in veined leaf; broad petals; and papillate acute lip with U.S.A., November 2016, M. Wilson & J. D. Werner shallowly bilobed glenion. PL0980 (paratype: COCO!). Plant small-to-medium in size, to ca. 15 cm tall, Etymology: In reference to the color of the sepals and epiphytic, caespitose; Roots fibrous, slender;Ramicaul petals which resemble the color of a “chestnut”, nut 10.2-12.1 cm long, enclosed by two sheaths, the upper

Figure 9. Lankester composite digital plate of Pleurothallis castanea: A. Whole flower. B. Whole plant. C. Leaf with flower. D. Lip with and without column. E. Column top view. F. Foral dissection. Prepared by Mark Wilson from the paratype Wilson & Portilla PL0958.

Figure 10. Drawing of Pleurothallis castanea: A. Whole plant. B. Whole flower. C. Floral dissection. D. Lip detail. Drawing by Jon Werner prepared from the paratype Wilson & Werner PL0980.

Figure 11. Lankester composite digital plate of Pleurothallis nangaritzae: A. Whole flower. B. Whole plant. C. Leaf with flower. D. Lip with and without column. E. Column side view. F. Floral dissection. Prepared by Mark Wilson from the paratype Wilson & Werner PL0977.

Figure 12. Drawing of Pleurothallis nangaritzae: A. Whole flower. B. Whole plant. C. Leaf with flower. D. Floral dissection. E. Lip. Drawings by Marco Jiménez and Luis Baquero prepared from holotype Tobar and Jiménez 2050.

LANKESTERIANA 16(3). 2016. © Universidad de Costa Rica, 2016. Wilson et al. — Three new species of Pleurothallis 363 sheath 0.85-1.3 cm long and the lower 2-4 mm long; Leaves deflexed, almost totally plain, ovate, acute, apiculate, shallowly cordate, 3.5-6.8 × 1.4-3.85 cm, glossy, coriaceous and heavily veined; Inflorescence one-flowered from reclining spathe 5-8 mm long, peduncle 2-3 mm long, pedicel 4-5 mm long, floral bract 3-4 mm long; Flower 10.7-13.3 × 7.8-10.0 mm, resupinate; Dorsal sepal beige with burgundy mottling, somewhat concave in apical half, elliptical-obovate to oblong-obovate, obtuse, entire along the margins, 5.0 × 3.0 mm, glabrous, 3-veined; Synsepal beige partially mottled with burgundy, slightly concave, ovate, obtuse, entire along the margins, 4.0 × 3.0 mm, glabrous, 5-veined; Petals beige mottled with burgundy, base entirely burgundy, ovate and shortly unguiculate, acute, marginally dentate, 4.5 × 3.2 mm, glabrous, 3-veined; Lip beige heavily mottled with burgundy, narrowly obovate, acute, marginally papillate-dentate, 3 × 2 mm, the glenion a small area in front of the Figure 13. Collection locations of Pleurothallis nangaritzae anther, bilobed, surrounded by narrow callus; Column (black star) and Pleurothallis rubrifolia (white star) in pink to pale burgundy with white along the edge of southeastern Ecuador (map from Wikimedia commons.) the clinandrium, stout, somewhat compressed dorsi- opened and at this time cannot be considered secure. ventrally, 1.0 × 1.5 mm, with a bilobed stigma, anther Whether the species occurs within the Bosque Protector apical, anther cap pale yellow, viscidium drop-like, Alto Nangaritza is unknown. The ex situ conservation orange. status is also of concern, since while the species occurs Additional material studied: Ecuador. Purchased in two collections in Ecuador, it is known from only from Mundiflora and flowered in cultivation by Jon one collection in the U.S. and likely all of these plants Werner in U.S.A., M. Wilson & J. D. Werner PL0977 originated from a single original plant. (paratype: COCO!). Discussion Etymology: Named for the type locality near the Nangaritza River in Zamora Chinchipe Province, Pleurothallis subsection Macrophyllae- Ecuador. Fasciculatae is the most speciose group within genus Pleurothallis as circumscribed by Pridgeon et al. Distribution and habitat: So far, Pleurothallis (2005), with between 223 and 297 species, depending nangaritzae is known in the wild from only the type on synonymy. The first author estimates that, even locality near the Nangaritza River, Province of Zamora conservatively, only ~60-70% of the species in the Chinchipe, Ecuador (Fig. 13): it has not, to date, been subsection have been described. Hence, a significant reported outside this Province and may be endemic amount of work will be required in this group in order to that region. P. nangaritzae grows as an epiphyte to describe the extant biodiversity before it is lost to adpressed to tree trunks in a lower montane forest at deforestation and climate change. Efforts should be an elevation of ~1500 m and occurs sympatrically directed to areas of high biodiversity and endemism with orchids such as Masdevallia strobelii H.R.Sweet which have received little attention by orchidologists & Garay, Maxillaria pachyacron Schltr., Oncidium to date: the northwest of Ecuador (Endara, Williams tipuloides Rchb.f. and Pleurothallis cordata Lindl. & Léon-Yánez 2009) and the southwest of Colombia, Conservation status: The type locality of Pleurothallis particularly the Department of Nariño (Orejuela nangaritzae occurs in an area in which a road has been Gärtner 2011), part of the Chocó bioregion; and

LANKESTERIANA 16(3). 2016. © Universidad de Costa Rica, 2016. 364 LANKESTERIANA the southeast of Ecuador (Endara et al. 2009) and adjoining areas of Amazonas, Peru. Unfortunately, the description of new species is somewhat hampered by the large number of superficially similar species in this group. We believe that the micro-morphology of the labellum and in particular the glenion, the structures with which the pollinator interacts directly, may be the most useful for distinguishing otherwise morphologically similar species in Pleurothallis subsection Macrophyllae-Fasciculatae. In this group, nearly all of which possess such a structure, the glenion is a small area of the hypochile, of distinct tissue structure, often depressed, but occasionally elevated on a callus, surrounded by tissue of completely different texture. While often mentioned in descriptions of species in the Macrophyllae-Fasciculatae, to our knowledge, it has not been examined in detail using SEM in this or any other group within Pleurothallis sensu Pridgeon et al. (2005). We hypothesize that it acts not just to attract the pollinator but that it serves Figure 14. Scanning electron micrographs of lip and column to position the pollinator in the optimal position for of Pleurothallis nangaritzae. SEM image by Katy pollinarium acquisition or deposition. Dupree. All three of the species described herein possess P. nangaritzae are present in hobbyist, commercial a glenion, but we were only able to obtain detailed and botanic collections in North and South America, images of the glenion of Pleurothallis rubrifolia. The ex situ conservation is a very poor substitute for glenion of P. rubrifolia was very distinctive, being in situ conservation in tropical montane forests somewhat elevated on a callus; apparently consisting (Orejuela Gärtner 2011). These forests, however, are of three cell types; and being surrounded by a smooth, extremely vulnerable due to deforestation and climate somewhat depressed area of the hypochile/mesochile change (Orejuela Gärtner 2011) and while modest (Fig. 6–7). The glenion of Pleurothallis nangaritzae orchid conservation efforts are underway through is bilobed, (Fig. 11b), a rare character in Pleurothallis organizations such as the Orchid Conservation Alliance subsection Macrophyllae-Fasciculatae, with few (OCA), EcoMinga in Ecuador and Salvamontes in papillae along the outer edges. The papillae cover a Colombia, significantly more effort and funding will large portion of the lip and surround a triangular area be required to conserve even a small fraction of the of smooth tissue, with the glenion at the base (Fig. diversity of these species in the coming decades. 14). The P. rubrifolia glenion was quite different from that in Stelis, in which Ignowski (2015) observed the Acknowledgements. The authors are grateful to Colorado glenion to consist of a less well-defined area of tall, College for research funding for Wilson and Dupree and slender, loosely packed, papillate cells. Based upon provision of greenhouse and herbarium facilities; to Dr. the observations of Ignowski (2015) in Stelis and the Ron Hathaway for assistance with SEM; to Ecuagenera, preliminary observations here, the utility of the glenion EquaflorA and Mundiflora for access to plant collections; in taxonomic discrimination of morphologically to members of the Portilla family for their warm hospitality; similar species and its specific role in the reproductive to EcuaCorriente for the facilities provided under Project ecology of Pleurothallis subsection Macrophyllae- Mirador and for the use of their investigation permit Fasciculatae deserves further study. allowing collection of the species described; to Ecotono for Although Pleurothallis rubrifolia, P. castanea and aid with the field logistics and the use of the transportation

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